Both options might be an option to increase alertness and awareness of chronic DOC patients. An akinetic mutism seems to be a positive and severe cerebral hypoxia a negative predictor. Epileptic seizures are a potential unwanted side effect. More clinical studies are warranted.

Background: Transcranial low-level laser therapy (T-LLT) proved promising in acute stroke studies and in single traumatic brain injured subjects (TBI). It was assumed to increase cortical mitochondrial energy production and/or vasodilatation.Objective: Within this case series the potential of transcranial low-level laser therapy in improving the alertness and awareness in TBI subjects with severe disorders of consciousness will be investigated. Methods:Following a 21-day baseline, the forehead of five patients, four chronic in a state of unresponsive wakefulness or minimal consciousness, one subacute in the state of akinetic mutism, was stimulated with the T-LLT (785 nm, 10 mW/cm 2 , CW mode, 21 emitting diodes) for 10 min every workday for six weeks. Follow-up was four weeks after end of intervention. Primary variable was the revised version of the Coma Recovery Scale (r-CRS, 0-23), blindly assessed by an external reviewer with the help of videos. Results:The r-CRS, almost stable during baseline, improved in all patients during the intervention, from 3 to 12, 9 to 12, 8 to 12 and 5-12 in the chronic, and from 6 to 21 in the subacute patient. Follow-up revealed a sustained effect. The patient in the state of akinetic mutism improved her competence in the activities of daily living and mobility status. Single epileptic fits occurred in two patients during the intervention.Conclusion: T-LLT improved the patients' alertness and awareness; epileptic fits were potential side effects. Sham-controlled studies including the quantitative assessment of awareness should follow the case series.

Background:Transcranial low-level laser therapy (T-LLT) proved promising in acute stroke studies and in single traumatic brain injured subjects (TBI). It was assumed to increase cortical mitochondrial energy production and/or vasodilatation.Objective: Within this case series the potential of transcranial lowlevel laser therapy in improving the alertness and awareness in TBI subjects with severe disorders of consciousness will be investigated. Methods:Following a 21-day baseline, the forehead of five patients, four chronic in a state of unresponsive wakefulness or minimal consciousness, one subacute in the state of akinetic mutism, was stimulated with the T-LLT (785 nm, 10 mW/cm 2 , CW mode, 21 emitting diodes) for 10 min every workday for six weeks. Follow-up was four weeks after end of intervention. Primary variable was the revised version of the Coma Recovery Scale (r-CRS, 0-23), blindly assessed by an external reviewer with the help of videos. Results:The r-CRS, almost stable during baseline, improved in all patients during the intervention, from 3 to 12, 9 to 12, 8 to 12 and 5-12 in the chronic, and from 6 to 21 in the subacute patient. Follow-up revealed a sustained effect. The patient in the state of akinetic mutism improved her competence in the activities of daily living and mobility status. Single epileptic fits occurred in two patients during the intervention. Conclusion: T-LLT